Buttercups like Ranunculus sp. are common on the moist arctic tundra.

This diverse family, containing 1500 species, is well represented by six genera in the Canadian Arctic. All buttercups are rooted, but the leaves of aquatic species can protrude from the water's surface, float on the water, or remain submerged. Several buttercup species thrive in Canada's Arctic, and each dominates a specific habitat. Floating buttercup, Ranunculus hyperboreus, white water-crowfoot, R. aquatilis, and yellow water-crowfoot, R. gmelinii, prefer ponds and other shallow-water habitats, while Lapland buttercup, R. lapponicus, commonly occurs in sphagnum bogs. Yellow marsh-marigold, Caltha palustris, prefers freshwater marshes and wet meadows.

The yellow marsh-marigolds of the Arctic are smaller and less showy than their temperate zone cousins. These differences are due to nutrient, temperature, and moisture limitations in the Arctic. The yellow marsh-marigold's scientific name, Caltha, means "cup" and refers to the shape of the flowers. The yellow marsh-marigold is, indeed, yellow; however, the glossy flower is composed of five large, yellow sepals and completely lacks true petals.